Our objective is to gain further understanding of the regulatory features of the utilization of glycerol and sn-glycerol 3-phosphate (G3P) by bacteria at genetic and enzymatic levels. The principal investigations will be on: 1) the control in Escherichia coli of the activities of the transport proteins through interactions with other permeation systems, especially those for carbohydrates that are used in preference to glycerol and G3P; 2) the regulation in E. coli of the synthesis and operation of two membranes associated and flavin-dependent G3P dehydrogenases by respiratory conditions or elements; 3) the nature of the specific inactivation process in Klebsiella aerogenes of the inducible nicotinamide adenine dinucleotide-linked glycerol dehydrogenase following the shift from anaerobic to aerobic growth on glycerol; 4) the relative functional merits of catabolic glycerol pathways initiated by dehydrogenation versus those initiated by phosphorylation; and 5) the purported unusual pattern for glycerol dissimilation by the strict aerobe Gluconobacter suboxydans. The studies will be carried out with the aid of mutant analysis both for locating the relevant genetic loci and for characterizing their function. The isolation and characterization of the membrane bound proteins will also be an important part of the methodology.